1. Field of the Invention
This invention relates in general to devices and equipment for cracking the shell of a nut.
2. Description of the Prior Art
In the past there have been a wide variety of devices utilized to crack nuts. The object of all these devices is to allow the shell to be separated from the edible meat portions of the nut. Some of these devices are machine operated to automatically and continuously load and crack nuts. Others are operated manually in either the loading process or the application of force to crack the nut.
Machines which automatically operate to load nuts into a position for cracking are shown in U.S. Pat. Nos. 676,187 to Grimm; 807,052 to Warner; 947,932 to Peckham; and 3,422,865 to Barrow. Each of these devices loads the pecan into a nut cracking position by mechanically orienting the nut into a cylindrical opening. The cylindrical opening is sized such that the nut will fit lengthwise through the opening and can enter in no other way. A disadvantage of the cylindrical opening is that it accomodates only one size of nut. Another disadvantage is that irregularities in the nut size and shape can clog the machine. Still another disadvantage is that the nut must be agitated or otherwise moved and oriented to allow the nuts to enter lengthwise into the cylindrical opening.
The prior art also shows a variety of ways for cracking the shell of the nut. U.S. Pat. No. 676,187 to Grimm shows a set of saws which are used to cut the shell at spaced locations around the nut allowing the nut to be opened with a slight pressure applied to the edges of the nut. Other devices such as U.S. Pat. No. 947,392 to Peckham operate to crack the shell of the nut by applying pressure to the sides of the nut. As shown by the Peckham patent many of these devices which operate to crack the nut by applying pressure to the sides of the nut have the pressure applying portion specifically shaped to conform to the side of the nut to be cracked.
U.S. Pat. No. 397,863 to Kuhlmann shows a device wherein a hammer is continuously operated to impact the side portion of a nut held in a reservoir location. The hammer is prevented from smashing the nut by a collar which stops the travel of the hammer.
U.S. Pat. No. 3,422,865 to Barrow shows a device which cracks the nut shell by applying pressure to the ends of the shell. In this process a cam moves a piston forwardly to engage and then crush the end of the shell. The opposite end of the shell is held in place by a stationary piston and lateral movement of the nut is prevented by a cylindrical wall which encloses the nut.
U.S. Pat. No. 3,713,468 to Walsh describes another device wherein pressure is applied to the ends of the nut in the cracking process. As with the Barrow device the Walsh device retains the nut within a cylindrical wall as the pressure is applied. The Walsh device utilizes a manually moved piston to engage the ends of the nut. The opposite end of the nut is held in place by a fixed jaw. After the nut has been cracked, the cylinder containing the nut is withdrawn and a nut rest pivots downwardly to allow the nut to fall into a drawer for retaining the cracked nuts.
A disadvantage of each of the above devices utilized in cracking nuts is that the pressure applied to crack the nut shell tends to crush the meat as well as the shell. This is especially a problem when nuts of different sizes are positioned in the nut cracker. Small nuts tend to reduce the amount of cracking force applied such that the nuts are not completely cracked and the shell cannot be separated from the meat. On the other hand, large nuts increase the cracking force such that the meat is crushed.
Another disadvantage of the prior art is that the nut must be precisely positioned to prevent improper application of the cracking force. This orientation is often provided by means of a cylindrical opening which can be clogged with cracked or uncracked nuts.
Still another problem with the prior art has been accommodating different types of nuts. Since different types of nuts have shells of varying hardness and thickness as well as varying sizes and shapes, the nut crackers of the prior art have not been satisfactory in accommodating different kinds of nuts. This is especially true where nuts are automatically loaded into the nut cracking position.
Another problem in the prior art has been that the machines used to automatically and continuously crack nuts have been extremely complicated and tend to malfunction requiring complicated repairs.